#include <bits/stdc++.h>
using namespace std;

#define int int64_t
#define endl "\n"

using PII = pair<int, int>;
using TII = tuple<int, int, int>;
template<class T>
using V = vector<T>;
using i64 = long long;
using i128 = __int128;
using u64 = unsigned long long;

#define FOR(i, a, b) for (int i = (int)(a); i <= (int)(b); i++)
#define FOR2(i, a, b, c) for (int i = (int)(a); i <= (int)(b); i += c)
#define FORD(i, b, a) for (int i = (int)(a); i >= (int)(b); i--)
#define FORD2(i, b, a, c) for (int i = (int)(a); i >= (int)(b); i -= c)
#define ALL(a) a.begin(), a.end()
#define RALL(a) a.rbegin(), a.rend()
#define lowbit(x) ((x)&(-x))
#define RE return;
#define Yes cout << "Yes" << endl;
#define YES cout << "YES" << endl;
#define No cout << "No" << endl;
#define NO cout << "NO" << endl;
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define sz size()

void solve() {
    int n,k;
    cin>>n>>k;
    V<int>a(n),b(n);
    for(auto& x:a)cin>>x;
    for(auto& x:b)cin>>x;
    int ans1=-1e18,ans2=1e18,t1=0,t2=0;
    int idx=k;
    FOR(i,0,k-1){
        t1+=a[i],t2+=b[i];
    }
    ans1=max(ans1,t1);
    ans2=min(ans2,t2);
    FOR(i,k,n-1){
        t1+=a[i];
        t1-=a[i-k];
        t2+=b[i];
        t2-=b[i-k];
        if(t1>ans1){
            ans1=t1;
            idx=i+1;
        }else if(t1==ans1){
            if(ans2>t2){
                ans2=t2;
                idx=i+1;
            }
        }
        
    }
    cout<<idx-k+1;
}

signed main() {
    int Task = 1;

    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    while (Task--) {
        solve();
    }

    return 0;
}